Whoever the group that did something like this at such a fun event as the Boston race had to be sick..
Like hurting kids on a school bus or the like.. All it does is create hate for their cause, or ideals. I don't give a damn what their political beliefs are..
What the hell do the idiots gain by doing such a stupid thing?
So many cameras there, even pre race time, they will narrow this down to who did this moronic deed.
I have been at the finish line for the Boston Marathon.. It is a good time party, fun and experience to see once in a lifetime, if you have not seen it before..
Sic em Law Enforcement and make them suffer in hell for their sickness.
Stupid sick mother friggers.. May they rot in hell, for what they or whoever did such a sick stupid thing..
Prayers on the way for all injured or sadly killed.

"Man needs but two things to survive alone in the woods. A blow up female doll and his trusty old AK-47" - Thomas Jefferson 1781